Combining search results from different sources such as internet and intranet search engines is an ongoing field of development. In many situations it is useful to have search results from several sources in view at the same time. For example, results from “paid for” web services, results from public archives, results from enterprises, results from a user's home network, results from social network services, results from content sources of different types.
Some existing approaches to combining search results from different sources merely show results from different sources in different parts of a results page. This minimal combination mechanism may be implemented without needing a server to combine the results. Other approaches use a merging server or other entity to combine the search results. Search requests are channeled through the merging server to different sources. The merging server may then receive results from the different sources and de-duplicate and merge the results before enabling them to be output to a user.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known systems for combining search results.